Re-enable the relative watch test
Re-enable the relative watch test

Note that Irmin will occasionally create duplicate watch events:
it is safe to ignore these.

Signed-off-by: David Scott <63c9eb0ea83039690fefa11afe17873ba8278a56@citrix.com>

mirage/ocaml-xenstore-server,djs55/ocaml-xenstore-server,mirage/ocaml-xenstore-server